Controller.



E. W. STULL.

CONTROLLER.

APPLICATION FILED JULY 20,1910. 1 ,O1 8 ,01 9, Patented Feb. 20, 1912.

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UNITED sTAgns en rnnr OFFICE.

l:EJYIIVIEJIT W. STULL, OF MILWAUKEE, WISCONSIN, ASSIGNOR TO ALLIS-CHALMERS COMPANY, A CORPORATION 0F NEW JERSEY..

CONTROLLER.

Specication of Letters Patent.

Patented Feb. 2o, 1912.

Application filed .Tuly 20, 1910. Serial No. 572,892.

`v It is the object of my invention to provide an improved form of controller, particularly in the. construction of the controll1er drum. This is accomplished by moldingl the drum body, lwhich is preferably 'mounted on a shaft of magnetic material,

l of some plastic insulating material, and

molding in this insulating d terial certain metal parts. The-re may be two sets of these metal parts, though in some cases either set may-be omitted. The plugs of one set` are for furnishing means for fastening the contactsegments to the drum body; and those of the other` are located near the ends of certain contact segments for the purpose of diminishing the reluctance of the magnetic path between the controller shaft and. certain other parts toassist the action of a magnetic blowout.

The. various novel features of my invention will be apparent from the description i and drawings, and will be pointed out inthe claims...

' 'Figure 1 is a horizontal section of acontroller embodying my invention; and F ig. 2 is a partial front, elevation of such controller, with the cover parts in section.

The controller frame' 10 has one or more inwardly extending projections 11 in which is journaled the controller shaft 12. On this controller shaftis a molded drum body 13, formed'in a suitable mold of some plastic insulating material. The ,drum body 13 particularly is fundamentally cylindrical in shape, but

has certain projections 14 in'which'are l0- cated iron parts 15. These parts 15 are preferably non-integral with the shaft 12 and are in the form of plugs flared attheir inner ends to obtain a firm anchorage in the insulating material forming the drum body. They extend from point-s close to the shaft 12 to points at or near the outer surfaces of the projections 14.- The outer ends of the plugs 154 are shown with internal screw threads,

removed and some which may be. provided for the vvpurpose of enabling such plugs to be held firmly in the mold. Other plugs 16, likewise iared at are also embedded in the insulating malterial forming the drum body 13. lThese plugs 16 are screw-threaded internally for two purposes; to enable them to be held .firmly in place during the molding operation, and to provide threads for engage- `their inner ends to provide an anchorage,

ment with the screws 17 which hold in place plates 18 on which the contact. segments 19 of the controller are mounted. The segments 19 cooperate with stationary contactv fingers 20, preferably located between insulating septa 21. An iron bar'22 is located. just beyond the ends of the contactiingers 2O in the same plane with such ends and the shaft, 12, and this bar 22 is 24, frame 10, projections 11, and shaft 12,'

and the ends of the fingers 20are located in the air gap between the bar 22and the shaft 12. Any breaking of circuits between the contact segments 19V and the contact lingers 20 thus takes place in this air gap,

and thus is disrupted magnetically. It is n in order to lessen thev length of4 this air gap and thus to increase the eiiiciency of the blowout `that the plugs 15 are provided, these plugs being located near thosefends of any or all of the contact segments 19 at which breaking of the circuit takes place.

Many modifications may be made in the precise arrangement shown and described, and all such which do notdepart from the spirit and scope ofv my-inventionl aim'to cover in the following claims.

What I claim asnew is: v

1. In ay controller, a shaft df magnetic material, a drunrmolded of plastic insulating materialen said shaft, a contact segment mounted on said drum, and an iron plug molded in such drum adjacent to an end of such segment.

2. In a controller, a shaft of magnetic material, a vmolded .insulating drum mounted on said shaft, contact segments mounted on said drum, contactiingers cooperating with said contact segments, means for producing a magnetic field extending from the shaft across the space occupied by the ends of said contact fingers, and parts of magnetic `material embedded in said drum adjacent to ends of said contact segments.

3. In a controller, a shaft of magnetic material, a molded insulating' drum mounted thereon, a contact segment mounted on said drum, a part of magnetic material embedded in the drum adjacent to an end of said contact segment, a contact finger cooperating With said segment, a plate of magnetic material on the other side of said contact finger from said drum, and means flared at its inner end and embedded n said.

drum.

Milwaukee, Wis., July 1, 1910.

Intes'tmony whereof I aifix'my signa ture, in the presence of two Witnesses.-

EMMETT W. STULL.

Witnesses I-I. C. CASE,

CLARA E. BENSEL. 

